The neutron emission rate is a crucial parameter for most of the radiation sources that emit neutrons. In the case of large fusion devices the determination of this parameter is necessary for a proper assessment of the power release and the prediction for the neutron budget. The 14 MeV neutron generator will be used for calibration of neutron diagnostics at JET and ITER facilities. The stability of the neutron generator working parameters like emission and angular homogeneity affects the accuracy of calibration other neutron diagnostics. The aim of our experiment was to confirm the usefulness of yttrium activation method for monitoring of the neutron generator SODERN Model: GENIE 16. The reaction rate induced by neutrons inside the yttrium sample was indirectly measured by activation of the yttrium sample, and then by means of the γ-spectrometry method. The pre-calibrated HPGe detector was used to determine the yttrium radioactivity. The emissivity of neutron generator calculated on the basis of the measured radioactivity was compared with the value resulting from its electrical settings, and both of these values were found to be consistent. This allowed for a positive verification of the reaction cross section that was used to determine the reaction rate (6.45 × 10−21 reactions per second) and the neutron emission rate (1.04 × 108 n·s−1). Our study confirms usefulness of the yttrium activation method for monitoring of the neutron generator.
1. Krokhin, O. N., Nikulin, V. Y., Peregudova, E. N., & Volobuev, I. V. (2005). Compact activation detectors for measuring of neutron emission on Plasma Focus installations. Problems of Atomic Science and Technology, Seria: Plasma Phys., 1(10), 101–103.
2. Jakhar, S., Rao, C. V. S., Shyam, A., & Das, B. (2008). Measurement of 14 MeV neutron flux from D-T neutron generator using activation analysis. IEEE Trans. Nucl. Sci., 248, 2335–2338.
3. National Nuclear Data Center, Brookhaven National Laboratory, based on ENSDF and the Nuclear Wallet Cards. (2014, February). Decay radiation search. Retrieved May 12, 2014, from http://www.nndc.bnl.gov/nudat2/indx_dec.jsp.
4. Jednorog, S., Scholz, M., Popovichev, S., Murari, A., & JET EFDA contributors. (2009). Numerical optimization of activation samples for the application of the activation technique to measure neutrons in large fusion devices like JET and ITER. (EFDA-JET-CP(09)06/03).
6. Bronson, F. L., & Venkataraman, R. (2000). Validation of the accuracy of the LabSOCS mathematical efficiency calibration for typical laboratory samples. In 46th Annual Conference on Bioassay, Analytical, and Environmental Radiochemistry, 12–17 November 2000. Seattle, Washington, DC.
7. Bronson, F. L., Venkataraman, R., & Young, B. (1998). Massemetric efficiency calibrations of HPGe detectors for Laboratory applications. In 44th Annual Conference on Bioassay, Analytical, and Environmental Radiochemistry, 15–19 November 1998. Albuquerque, NM.